From: hal@pollux.cs.uga.edu (Hal N. Brooks)
Newsgroups: comp.os.linux.misc
Subject: sxpc critic recants (data included)
Date: 18 Nov 1993 10:00:14 GMT
Organization: University of Georgia, Athens
Message-ID: <2cfh3e$7mp@hobbes.cc.uga.edu>
In short, this critic of SXPC must confess that it is useful.
My previous, less formalized observations were made with
respect to sxpc-0.9, but this more objective look made use
of sxpc-1.01, which I believe has benefitted from some
enhancements.
For those who want the executive summary, below (from worst to
best) are what I assess to be the advantages of using various
compression techniques with X11.
V.42bis: 84% speedup
Sxpc compression: 109% speedup
V.42bis + Term compression: 123% speedup
Term compression (i.e., txconn): 128% speedup
V.42bis + Term compression + Sxpc compression: 146% speedup
Term compression + Sxpc compression: 147% speedup
V.42bis + Sxpc compression: 148% speedup
In brief, it is counterproductive to use TERM compression along
with V.42bis compression, presumably because they are based on
the same algorithm. Therefore, if you use TERM compression (without
SXPC), you should see a 2% speedup by disabling V.42bis.
If your modem doesn't have V.42bis compression, then you are well
served by using a combination of SXPC and TERM compression.
If you do have a modem with V.42bis compression, you should see a
speedup of about 9% by using SXPC in conjunction with V.42bis, over
using TERM compression a